Discovery of improved and economical systems and methods for extracting hydrocarbons from organic-rich rock formations, such as oil shale, has been a challenge for many years. Historically, a substantial amount of hydrocarbons are produced from subterranean reservoirs.
The reservoirs can include organic-rich shale from which the hydrocarbons derive. The shale contains a hydrocarbon precursor known as kerogen. Kerogen is a complex organic material that can mature naturally to hydrocarbons when it is exposed to temperatures over 100° C. This process, however, can be extremely slow and takes place over geologic time.
Immature oil shale formations are those that have yet to liberate their kerogen in the form of hydrocarbons. These organic rich rock formations represent a vast untapped energy source. The kerogen, however, must be recovered from the oil shale formations, which under prior known methods can be a complex and expensive undertaking, which may have a negative environmental impact such as greenhouse gases and other emissions and effluents, such as carbon dioxide and other gases and liquids.
In a known method, kerogen-bearing oil shale near the surface can be mined and crushed and, in a process known as retorting, the crushed shale can then be heated to high temperatures to convert the kerogen to liquid hydrocarbons. There are, however, a number of drawbacks to surface production of shale oil including high costs of mining, crushing, and retorting the shale and a negative environmental impact, which also includes the cost of shale rubble disposal, site remediation and cleanup. In addition, many oil shale deposits are at depths that make surface mining impractical.
Attempts have been made to overcome the drawbacks of prior known methods of recovery by employing in situ (i.e., “in place”) processes. In situ processes can include techniques whereby the kerogen is subjected to in situ heating through combustion, heating with other material or by electric heaters and radio frequencies in the shale formation itself. The shale is retorted and the resulting oil drained to the bottom of the rubble such that the oil is produced from wells. In still other attempts, in situ techniques have been described that include fracturing and heating the shale formations underground to release gases and oils. These types of techniques typically require finished hydrocarbons to produce thermal and electric energy and heat the shale, and may employ conventional hydro-fracturing techniques or explosive materials. These attempts, however, also continue to suffer from disadvantages such as negative environmental impacts, high fuel costs to produce thermal energy for heating and/or electricity, as well as high water consumption. In addition, these methods may have a negative environmental impact such as greenhouse gases and other emissions and effluents, such as carbon dioxide and other gases and liquids.
Therefore, it would be desirable to overcome the disadvantages and drawbacks of the prior art with a method and system for recovering hydrocarbon products from rock formations, such as oil shale, which heat the oil shale via thermal or electrically induced energy produced by a nuclear reactor. It would be desirable if the method and system can accelerate the maturation process of the precursors of crude oil and natural gas. It is most desirable that the method and system of the present invention is advantageously employed to minimize energy input costs, limit water use and reduce the emission of greenhouse gases and other emissions and effluents, such as carbon dioxide and other gases and liquids.